A well-cultivated mind is, so to speak, made up of all the minds of preceding ages; it is only one single mind which has been educated during all this time.

It is the passions that do and undo everything.

A work of morality, politics, criticism will be more elegant, other things being equal, if it is shaped by the hand of geometry.

A philosopher will not believe what he sees because he is too busy speculating about what he does not see.

Mathematicians are like lovers. Grant a mathematician the least principle, and he will draw from it a consequence which you must also grant him, and from this consequence another.

Since the princes take the Earth for their own, it's fair that the philosophers reserve the sky for themselves and rule there, but they should never permit the entry of others.

I feel nothing, apart from a certain difficulty in continuing to exist.